Alternative facts: a reconsideration of putatively natural interspecific hybrid specimens in the genus Heliconius (Lepidoptera: Nymphalidae)AuthorBrower, Andrew V. Z.textZootaxa20182018-10-1244991187journal articlehttps://doi.org/10.11646/zootaxa.4499.1.11175-53261459174A191D47C-AA66-4A95-8ED1-2B494EFC8F0E
Putative
H. cydno cordula
x
H. melpomene melpomene
hybrids from Venezuela
A series of specimens from
Táchira
in western
Venezuela
exhibit what appear to be intermediate
H. cydno
x
H. melpomene
phenotypes. Apparent hybrids have been collected in this area since at least 1980, so it seems that there is a stable hybrid zone of some sort that has persisted for at least 35 years. Many of the more recent hybrid specimens were genotyped with
AFLP
markers by
Mávarez
et al.
(2006)
, who said, "the hybrid individuals cannot be distinguished from other individuals of
H. cydno
, indicating that multiple generations of backcrossing must have occurred." This is an odd result—particularly given that even the putative F1 backcross to
H. melpomene
(Mávarez Hybrid #34,
Fig. 135
) has an essentially pure
H. cydno
genotype at the
AFLP
loci.
Brower (2011)
predicted that these specimens might represent not interspecific
H. cydno
x
H. melpomene
hybrids, but hybrids between
H. cydno cordula
and an unrecognized red-banded member of the
H. cydno
clade. In light of the genetic evidence, and given the number of recently-discovered
H. cydno
cognates on the east side of the Andes, this hypothesis seems at least as parsimonious as an interspecific cross. Therefore, all of the
Táchira
specimens (Mávarez Hybrids #28-#34 and Hybrids #87-#96 from the Mallet
et al.
(2007) database are interpreted as interracial, not interspecific hybrids, and given an identity score of zero. This is clearly an important area for further investigation to fill in our understanding of the distribution and phenotypic variation of the
H. cydno
—
H. heurippa
clade.

FIGURE 143.
Hybrid #94 (dorsal). Venezuela: Táchira(?), ~1980. This specimen is probably in the Romero family collection, Maracay. Interpreted by Mallet
et al.
(2007) as a
H.
cydnogadouae
(Fig. 144) x
H.
melpomenemelpomene
(Fig. 128) F1 backcross to
H.
cydno
.
H.
cydnogadouae
has a white apical band and sometimes also a row of submarginal dots on the FW and a subapical white spot on the HW. Given the absence of white apical markings on the FW, this is probably another
H.
cydno
(Fig. 127) hybrid.

FIGURE 145.
Hybrid #95 (dorsal, ventral). Venezuela: Barinas, Above Barinitas, 900 m, (no date) In the Mattei family collection. Interpreted by Brown & Fernández (1985) and by Mallet
et al.
(2007) as a
H.
cydnobarinasensis
(Fig. 146) x
H.
melpomenemelpomene
(Fig. 128) F1. These photos are underexposed. In Brown & Fernández (1985, Fig. 177), there is clearly a partial hourglass mark in the FW discal cell and a shadowy submarginal white band on the dorsal and ventral hindwing. Nevertheless, the brick-red distal forewing band is not found in the local
H.
melpomene
.